Increasing agricultural production in a sustainable way and mitigating the effects of climate change are two of the most important challenges facing the modern world. These challenges include a need for higher crop yields, a need to make degraded soils more productive, and a need to manage for productive agriculture with less dependable water resources. Some efforts have been made to reduce the long-term negative effects of agriculture by crop-rotation and organic farming. Efforts have been made to address climate change by reducing avoidable greenhouse gas emissions through production of renewable energy and off-setting unavoidable emissions through sequestration of carbon in the environment. Some carbon sequestration efforts have been aimed at storage of carbon in soil and of carbon dioxide in geologic formations. However, due to the inherent lack of long-term stability of plant derived biomass storage of carbon derived directly from plant biomass is not a long-term solution. Pyrolysis of biomass to produce a solid material called char, charcoal or more specifically biochar, which can be a product that is tailored for use as a soil amendment, can play a significant role in both of these efforts related to climate change and agriculture, but is currently limited by the use of biochars that exhibit instability or degradation and which may have positive or negative effects on soil flora, fauna and/or plant growth. Therefore, there is a need for improved methods, devices, and systems for the production of stable and/or beneficial biochars.